Rian Johnson has said that The Last Jedi doesn't go too deep into explaining Supreme Leader Snoke's backstory, but a new book has revealed a couple of new details about the mysterious puppet master of the First Order.
DK's Star Wars: Absolutely Everything You Need To Know book has been expanded as part of the 'Journey to The Last Jedi' marketing push, and scans of the new pages have emerged on Reddit (via Star Wars News Net). There are a few snippets in there about various characters, but the most intriguing pertain to Snoke:
"Among Snoke's many frightening powers are telepathy, and Force chokes and throws."
It confirms the long-held belief that Snoke is indeed Force-sensitive - as suggested by his training of Kylo Ren, and his "There has been an awakening..." line, along with giving us some clues as to what we can perhaps expect to see in The Last Jedi.
The part about telepathy is particularly interesting. In the novelisation of The Force Awakens, Rey hears a voice in her head urging her to kill Kylo Ren during their duel. The idea of Snoke having telepathy is the closest we've come yet to knowing it was him, as an attempt to turn her to the Dark Side after realising Kylo's weakness.
The book also confirms that Snoke has eight Praetorian guards, and that they are definitely human rather than droids or aliens. It also reveals that Luke Skywalker has been on Ahch-To for "many years", which fits with the events of the novel Bloodline.
How much these will factor into the movie itself remains to be seen, but with a new trailer expected early next week we shouldn't have to wait long to get more clues about how Episode VIII is shaping up.